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ADS42JB46: ENOB Test : Choose which SINGLE FRECQUENCY FILTER? Which Frequency?

Part Number: ADS42JB46

Hi TI, 

I design one ADS42JB46 Test Board following the official design 'ADS42JB46EVM'.

Now I want to test the performance(ENOB) of  ADS42JB46 chip.

I want to test ENOB under several specific frequency as the you do, so I can compare my results with the official results. 

  

Q1:  I need to know which Frequency is the Reference because I only find one frequency input for ENOB test in ADS42JB46 datasheet.

And I find several frequency input for SNR test:

So I should test under 10MHz/70MHz/170MHz/230MHz ?

Q2: By the way, I want to choose one good Narrow band pass filter(for SINGLE FREQUENCY PASS) to filter noise because my Anolog-Source is not good,  which Filter may I use? 

Best Regards, 

Nan

  • Hi Nan,

    Q1:  I need to know which Frequency is the Reference because I only find one frequency input for ENOB test in ADS42JB46 datasheet.

    And I find several frequency input for SNR test:

    So I should test under 10MHz/70MHz/170MHz/230MHz ?

    This will depends on your actual ADC usage in your end application. The typical usage of the ADS42JB46 is used at ~170MHz for wireless infrastructure radios.

    Q2: By the way, I want to choose one good Narrow band pass filter(for SINGLE FREQUENCY PASS) to filter noise because my Anolog-Source is not good,  which Filter may I use? 

    We use filters from TTE, which has very good spur rejection. Since your source may not be very good, you may still have limited noise performance which the bandpass filter cannot reject (i.e. the close in phase noise that is within the band pass filter pass band). Please do these tests with good quality signal generators such as R&S SMA100B or at least the SGS100A.

    -Kang

  • Hi Kang,

    For Q1, you said:"This will depends on your actual ADC usage in your end application. The typical usage of the ADS42JB46 is used at ~170MHz for wireless infrastructure radios."

    Yes I agree that point, but now I want to check if my ADS42JB46 test board is work normally as the datasheet shows.

    So I want to get several reference frequency points to get the ENOB, SNR or something. I want to know which frequency points are your choice when you test the ADC performance after you designed this chip.

    Best Regards,

    Nan

  • Hi Nan,

    you can refer to the following table for the points that we had tested

  • Hi Kang

    Thank you very much!

    By the way, if the filters you use is adjustable?

    I don't find one adjustable filter from TTE.

    Best Regards,

    Nan

  • Nan,

    You can find various companies making tunable filters. You can find one for example at K&L

    www.klmicrowave.com/.../

  • Hi Kang,

    Thanks, I have find one tunable filter from K&L.

    Best Regards,

    Nan